This project will develop a practical method for isolating granulocytes and platelets from whole blood. The cell suspension will be tagged with lipophilic chelating agents such as 8-hydroxy-quinoline complexed with 99mTc, 111In and 203Pb and re-injected intravenously for localization of abscesses, other focal inflammatory lesions, thrombi and infarcts by scintillation camera techniques. The efficacy of detection will be compared with that of conventional radiopharmaceuticals such as 67Ga citrate and I125 fibrinogen in dogs with induced abscesses and thrombi before human trials. Radioactive complexes of a variety of lipophilic chelates will be compared with 8-hydroxyquinoline for their ability to label isolated blood cellular components. BIBLIOGRAPHIC REFERENCE: Subramanian, G., McAfee, J.G., Gagne, G.M., Henderson, R.W., Rosenstreich, M. 99mTc-Oxine: A New Lipophilic Radiopharmaceutical For Labeling Leukocytes And Platelets. Proceedings of the 14th International Meeting of the Society of Nuclear Medicine, Berlin. Sept. 15-18, 1976.